Hey, It Almost Looks Like a Bridge

Columns that will form the support of the new Manette Bridge rise out of the Port Washington Narrows.
(Photo by Josh Farley | Kitsap Sun)

BREMERTON - The Manette Bridge be closed from 7:30 a.m. to 4:30 p.m. Monday through Wednesday for its annual inspection. Bicyclists and pedestrians will still have access to it. It will also close at 8 p.m. Wednesday until 8 p.m. Thursday to pour concrete for the replacement bridge being built nearby.

Drivers should also plan for possible delays crossing the Warren Avenue Bridge. One lane in each direction will be closed nightly Sunday through Thursday for the installation of railing. One northbound lane will be closed from 7 p.m. to 6 a.m. and one southbound lane from 8 p.m. to 6 a.m.

Five piers in different stages of construction in the Port Washington Narrows provide a step-by-step guide to building a new Manette Bridge.

Some of the piers are little more than 12-foot-diameter steel casings barely sticking out of the water; others are concrete columns climbing near roadway level. Though construction is coming right along, a green barge, red-and-white cranes and other massive equipment still dwarf the emerging span.

In a few days, crews will peel yellow-steel forms off Pier 2, exposing the first concrete column.

When people see that, state Department of Transportation project engineer Jeff Cook said, they'll say: "Oh, that's what the bridge is going to look like."

The $57.8 million concrete structure will replace a statuesque but crumbling steel truss bridge built in 1930. Construction began in August and will be wrapped up in late 2011 or early 2012. The old bridge will be closed during the last four months with traffic detoured to the Warren Avenue Bridge.

Here's a primer on work to date:

* A pair of long steel tubes, 12 feet in diameter and more than an inch thick, are lowered through the water and muck. They're driven 5 feet into hard ground with a vibratory hammer. Their tops stick up out of the water.

* A machine that works like a 12-foot-wide post hole digger augers the muck and dirt out of the steel tubes, or casings. The spoils are hauled away.

* A crane lowers a cage of reinforcing bar nearly as tall as the casings into the casings; the casings are filled with concrete.

* The work platform is moved to another pier site, leaving just the tops of the casings sticking out of the water.

* An oval concrete shell, about 55 feet by 24 feet with cutouts for the steel casings, is lowered over the casings and rests at water level on supports built into the casings.

* A foot of concrete is poured into the shell to tie it and the shafts together.

* The shaft tops are cut off almost flush with the just-poured concrete.

* Smaller reinforcing bar cages, 7 feet in diameter, are stood up on the shafts. These are for the concrete columns.

* The oval tub is filled with reinforcing steel and concrete is poured in it to tie the oval shell, shafts and column cages together as one structural unit.

* Yellow steel forms are placed around the rebar cages, and concrete is poured for the columns.

People can watch the new bridge take form from the old bridge.

"You don't get this close to many projects," Cook said. "Just the magnitude of it, the fact that it's built from the water and that people are right on top of it watching it happen" makes for a neat project.

Cook says he bumps into people all the time on or near the bridge who have been following the project for more than a decade and know it inside out.

"It's a little bit different, but it's good," Cook said. "We're building it for them."

Contractor Manson-Mowat is on schedule and making good progress, Cook said.

For more information about the project, visit http://www.wsdot.wa.gov/projects/sr303/manettebridgereplacement/.